The Memphis appeal. [volume] (Memphis, Tenn.) 1886-1890, 1887-05-15
FORESTS AND RAINFALL.
A LESSON FOR THE PEOPLE OF
THE TEXAS PRAIRIRs
VINO Are Suffering From Dr0uth-
A simple Remedy for IL Quite
Within Their Reach.

Scribner's Magazine: T tsnele OF
decsyed vegetauon which covers the
ground beneath the forest is of consd.
cradle thickness. Ga top il consists
altogether OF the deCayed trunks,
b anches and leave but it shades
downward into ordinary dark colored
soil at the depth Of few feet from the
suffice. This, the decay Of the zlne
of the forest, lies between the boughs
of the air and the branches of the
roots. Ia it 20 on he most imp r.
tant actions which take place in our
furest-sctions which affect the histo-
ry of land and sea. We shall there
fore have to consider it in somewhat
psinstaking way. The most evident
eff, ct of this shest CT deCaylpg wood
and moss which leeds on the decay, ia
on the rainfall of the region which it
mant 90. When, after a sessln Of
drought, copious rain falls upon this
spon9y mas, the water g for lorg
time absorbed in the interstices and
does not flow to the rivers. Even in
times OF very heavy rain the water
is slowly yielded 10 the streams;
a ter dry period of many weeks this
sponge retains good share Of water
A like amount Of rain falling on titled
fields or piajries slips quickly away to
the rivers, and thence 10 the sea. The
fret result ia, that when the land 10
destitute Of forests 1t sheds W ter like
houle roofs, breeding floods after every
considerable ran, while in the forests
the ram is only slowly yielded to the
stl cams. A second and less evident
result of the spongy character of the
forest bed is that, by hindeIing the
escape Of the rain water to the rivers,
1t increases the actual rainfall OF the
country. To see the nature and i'm.
portance Of this action, we must turn
aside for moment 10 consider the
origin OF the rain which falls upon the
land. The original source OF this va.
ter supply is the sea, which sends into
the lands tolelaSly regular annual
supply of moisture. When this falls
as rain or snow, eitt er Of two things
may happen-the water may 20 away
directly to the sea, or it may return to
the atmosphere as vspor 10 be again
precipitated as rain. The chance OF
its re-evspoIatioR is determined
by the speed with which it
flows TO the streams. From treelees
region 1t a idly escapes; in an exten.
sive district OF virgin forest it may
again and sgain pass from earth to air,
and from air to earth. The columns
OF vapor, which in times of summer
rain may be seen ascending from every
gre at wood, afford visible evidence OF
the effect of forests on rainfall. They
slso may show the observer some OF
the most beautiful phenomena Of at
moepheric circulation. In a summer
rain shower, the air above the trees be-
comes much cooler than 1t does In the
receeses below their tents of foliage.
This heated air within the woods
seeks to rise, and escapes in great col.
umns wherever there is a wide gap be.
tween the branches; as soon as 1t Ct
tains the cooler level above, the mois.
ture ia condensed, and the air, b. fore
transparent, becomes charged with
steam. To replace this ascending air
a bread current drafts toward
'ho OlhUiBibB ptICh"n VI NEpUT,
commonly from the higher parts
of the forest, where the air, owing to
the elevation OF the site, is cooler than
in the lower levels.
This repeated passage OF moisture
from earth to cloud, and from cloud to
earth, greatly increase the amount Of
foIca which the rain applies, in its fall
ing drops, to the earth's surface; but |
the rank vege alton protects the sur.
iace from the erosion which it would
other wise bring about Even the for
est clad hillaides OF the Cumberland
where the soil lies on de-
cliviti 8 Of great steepnees, cutter little
wear aslong as their natuTa protection
is left TO them. But a soon as they
are stripped OF the garment of wood
which has been upon the region ever
since, in the far off agee, they came
from the depths Of the sea, they wear
with great rapidity. The erosion is
limited, as long as they are forest clad,
to the stream beds, aud there is him
dered by the iRnumeTable obstacles of
the fallen trees and entangled drift
wood. The brooks which are
strong enough to clear their beds
and cut into the earth and
rock, are few in number; we may
often, on the hatter ground, find
racks Of square mile or more In
area in which there is not single
stream that ever assails the surface Of
the earth. AS sooD, however, as the
forest mat is removed, the surface be-
comes stained with channels; they
often, on the deforested surface, in
ere ,se 100 fold in their length, snd
more thanHha measure in their de-
structlve power. Relieved Of the re-
3traint from fallen timber, or the close
knit roots which enmesh the earth,
they sweep the precious soil away